In many situations, it is desirable to get “close” to an object without moving physically closer. A zoom control on a camera enables capture of images in which objects in the images can be magnified to obtain closer images of the objects. The zoom control on a camera also enables capture of images using a wide angle of view.
Cameras today often include a zoom lens, which includes a mechanical assembly of lens elements for which a focal length (and thus angle of view) can be varied, as opposed to a fixed focal length (FFL) lens. Using a zoom lens, objects in images can be made to appear larger than actual size. A zoom lens can be used with still images, video, motion picture cameras, projectors, some binoculars, microscopes, telescopes, and other optical instruments.
There are two types of zoom features that are generally used. Optical zoom uses mechanical optics (e.g., lens) of a camera to bring an object closer, for example, by moving the lens farther from an image sensor inside the camera body to increase zoom since a smaller portion of a scene will strike the image sensor, resulting in magnification. In contrast, digital zoom processes captured images to enlarge a portion of an image, and thus, simulate optical zoom. In examples, the camera crops a portion of the image and magnifies a result of the cropping. The magnification process is called interpolation. To make the cropped area bigger, digital zoom makes up, or interpolates, pixels to add to the image, which may give less than satisfactory results. In so doing, image quality can be lost. Using the digital zoom allows magnification of objects while sacrificing image quality to capture the moment.